Electrospun fiber membranes from blends of poly(vinylidene fluoride) with fouling‐resistant zwitterionic copolymers

Abstract

Nonwoven super‐hydrophobic fiber membranes have potential applications in oil–water separation and membrane distillation, but fouling negatively impacts both applications. Membranes were prepared from blends comprising poly(vinylidene fluoride) (PVDF) and random zwitterionic copolymers of poly(methyl methacrylate) (PMMA) with sulfobetaine methacrylate (SBMA) or with sulfobetaine‐2‐vinylpyridine (SB2VP). PVDF imparts mechanical strength to the membrane, while the copolymers enhance fouling resistance. Blend composition was varied by controlling the PVDF‐to‐copolymer ratio. Nonwoven fiber membranes were obtained by electrospinning solutions of PVDF and the copolymers in a mixed solvent of N,N‐dimethylacetamide and acetone. The PVDF crystal phases and crystallinities of the blends were studied using wide‐angle X‐ray diffraction and differential scanning calorimetry (DSC). PVDF crystallized preferentially into its polar β‐phase, though its degree of crystallinity was reduced with increased addition of the random copolymers. Thermogravimetry (TG) showed that the degradation temperatures varied systematically with blend composition. PVDF blends with either copolymer showed significant increase of fouling resistance. Membranes prepared from blends containing 10% P(MMA‐ran‐SB2VP) had the highest fouling resistance, with a fivefold decrease in protein adsorption on the surface, compared to homopolymer PVDF. They also exhibited higher pure water flux, and better oil removal in oil–water separation experiments. © 2018 Society of Chemical Industry

Thermal properties and structure of electrospun blends of PVDF with a fluorinated copolymer

“…Electrospinning (ES) is another popular fabrication method used to make fibrous membranes, due to its simplicity and scalability. The approach adopted in this work involves creating hydrophobic polymer blends and fabricating them into nonwoven fibrous membranes by ES.…”

“…Common approaches include use of ultrathin layers of material employing deposition techniques on substrates, [19][20][21][22] spin casting, 20 solution-casting, 21 and nonsolvent induced phase separation processes. [22][23][24] Electrospinning (ES) is another popular fabrication method used to make fibrous membranes, [25][26][27][28] due to its simplicity and scalability. The approach adopted in this work involves creating hydrophobic polymer blends and fabricating them into nonwoven fibrous membranes by ES.…”

Current and Emerging Approaches to Engineer Antibacterial and Antifouling Electrospun Nanofibers

“…Small diameter vascular grafts were created by electrospinning blends of polyurethanes with sulfobetaine groups; the polyurethanes provided a matrix that was elastic and biodegradable [ 147 ]. Recently, the nanofiber mats that have been electrospun from mixtures of poly(vinylidene fluoride) and random zwitterionic copolymers of poly(methyl methacrylate) and sulfobetaine-2-vinylpyridine (SB2VP) demonstrated a fivefold reduction in bovine serum albumin adsorption versus homopolymer poly(vinylidene fluoride) nanofibers [ 148 ]. Additionally, Ozcan et al have electrospun the zwitterionic amphiphilic copolymer poly(trifluoroethyl methacrylate-random-sulfobetaine methacrylate) (PTFEMA-r-SBMA) into very hydrophobic (~140°) nanofibers that resisted the bovine serum albumin adsorption [ 149 ].…”

Poly(vinylidene fluoride) (PVDF)/PVDF‐g‐polyvinylpyrrolidone (PVP)/TiO2 mixed matrix nanofiltration membranes: preparation and characterization

“…Hence, to prepare effective membranes, the hydrophilicity of PVDF membranes should be enhanced. 12,13 Numerous techniques, e.g. physical blending, 14 chemical grafting 15,16 and surface modification, 17 have been utilized recently to enhance the hydrophilicity of PVDF membranes, among which blending of organic and inorganic additives with polymeric materials is considered a simple and efficient method.…”